Tempo box



i 1,636,911 J`uly 26 1927* E. A. HUsEBY TEMPO BOX Filed May 15. 1926Patented July 26, 1927.

UNITED STATES PATENT OFFICE;

EDMOND HUSEBYV, OF CHICAGO, ILLINOIS.

TEMPO Box.

Application filed May 15,

- boxes commonly having associated therewith a valve for effecting therapid rerolling of the sheet, and also a. stabilizing device usuallyconsisting of a Vvalve in the suction passage from the roll motor to'the vacuum chest or suction pump that is` controlled by a pneumaticsubjected on one side to spring action and on the opposite side to thevacuum existing in the tempo box, and operating toautomatically*neutralize the variations in the pressure existing inthesystem during the playing of a piece.'V

One object of my present invention is to provide a very simple,inexpensive and compact device for performing the above-noted functions.Other objects are to provide an improved automatic vacuum stabilizingde- V vice, including improved means iter adjusting the sensitivenessand responsiveness thereof, to provide an improved throttle valvemechanism, and to provide an improved reroll valve. OtherI objects andattendant advantages of the invention will be apparent to personsskilled inthe art as the i same becomes better understood by referenceto the following-detailed description, taken in connection with theaccompanying drawings wherein I have illustrated one practical andapproved embodiment of the invention, and in whichw Fig. `1 is avertical longitudinal section,l

taken on the line 1-1 of Fig; 2;

Fig. 2 is a horizontal section taken on the line 2-2 of Fig. 1;

Fig. 3. is a vertical longitudinal section through the bottom Wall ofthc box taken on the line 8.-3 of Fig. 2; and F'g. 4 is a verticaltransverse section taken `on the line 1r-f4 of Fig. 2.

Referring to the` drawings, the tempo box shown therein is a hollowrectangular Wooden structure, comprising a relatively thick bottom Wall10, side walls 11, end' Walls 12,`and a top Wall or cover 13' detachablymounted on the upper edges of the side 1 and end Wallsas by screws ltandrendered f air-tight bysuitable gasket 15.

In and rsubstantially centrally ot the bot- I tom wall lOfis formed alongitudinal duct 19213.y Serial No. 109,294.

16 that at its inner end opens into the interior ot the box through a.port 17 and at its outer end communicates with an elbow nipple 18, whichlatter is connected bythe usual rubber tubing to the vacuum chest in iWhich a partial vacuum isconstantly maintained lthrough the action ofexhaustersor a suction pump. Surrounding the port 17 is an yannularWasher 19 of leather or like material constituting a valve seat.

In one side of the bottom Wall 10, parallel With the duct 16,l is formeda round bore 20 in which is tightly fitted a thin sheet-metal tube 21,one end ot which projects ythrough one of the end Walls 12 in the formofza nipple 21, to Which is connected a tube leading y to the music rollmotor.

In theY upper portion of the. bottom yWall ot the boxv directly over thehole 20 is formed an oblong slot 22; and theportion wherein the plungervalve is 'fully retracted,`

the tapered port 23 is wholly uncovered and the fullv strength ofthesuction is exerted through the nipple 18, duct- 16, port 17, port 23,tube 21 and nipple 21 upon the music roll motor. Vhen the plunger 24: ispushed. inwardly to partially closey the port 23,.the

flow passage is correspondingly throttled, and the speed of ythe musicroll motor reduced, in a manner Well understood in devices oi thischaracter.

The pressure stabilizing device in this case comprisesy a pneumaticWithin the tempo box, the movable side ot which carries a valve thatserves to more or less throttle the port 17. Heretofore, so far as I amaware, in pressure-stabilizing devices of this type the valve-carryingleaf of the pneumatic has been actuated in valve-closing direction by aspring, and in valve-opening direction by the suction existing Withinthe box. K4My present invention reverses these opposing iniiuences byanimproved construction which also permits both a rough, and a tineadjustment of the sensitiveness Voi: the stabilizing pneumatic. Attachedto the. under side of the cover-plate 13 "is a tapered wooden block 26forming the fixed side of the stabilizing pneumatic, to which isconnected, through the usual bellows cloth, the hinged or movable side27. Attached to and projecting forwardly of the swinging end of the side27 is a finger 28 in which is anchored the lower end of a pull spring 29that is housed in a tube 30 mounted in the cover-plate 13. The upper endof the s )ring 29 is attached to a cap screw 30 tlireaded through atapped aperture in the upper end of the tube 30 and equipped .with alock nut 31 for securing it in set position. Maiiifestly, the pull ofthe spring 29 tends to maintain the stabilizin pneumatic in collapsedposition against tliie opposing pull of the suction within the box, witha strength dependent upon the adjustment of the spring 29. On

the under side of `the movable leaf 27 of the manifestly acting to more.or less throttle the port 17 accordingly as the stabilizing pneumatic isexpanded by the vacuum or collapsed bythe spring 29.

The spring 29 having been roughly adjusted toa strength adequate toafford approximately the normal or desired pressure inthe vacuumchamber, the sensitiveness of the ueumatic may be more finely adjustedby die device shown in Fig. l, comprising an atmospheric duct to theinterior of the pneumatic that is controlled by a finely regulabledevice such as a needle valve. This.

device, in the form herein shown, consists of a short tube 34C mountedin the coverplate 15 with its lower end in register with a hole 35formed through the block 26 and o ning into the interior of thepneumatic.

e tube 34 is formed with an enlarged head 36 containing Ia valve seat37, which latter in turn is more or less throttled by a needle valve 38having screw-threaded engagement with 'the head 86 and secured inadjusted ition by a lock nut 39'. In opposite si es of the head 36 areholes 40 through which' atmospheric air, in amounts permitted byadjustment of the needle valve, can flow into the interior of thepneumatic as the latter is expanded by the pull of the suction on itsunder side. Manifestly, when the vent duct last described is nearlythrottled, Athe vacuum in the box works not merely against the pull ofthe spring 29 but against a parta vacuum within the pneumatic; whereas,when the vent duct is open suliiciently to freely admit atmospheric air`to the interior of they pneumatic in response to the expanding movementof the latter, the vacuum inthe box Works only against the pull of thespring 29. By manipulating the needle valve 38 in or out, the effect ofthe spring 29 in opposing the vibrations of the valve 33 may beincreased or diminished without adjusting the ten-sion of the spring 29and to a finer extent than can be secured by such adjustment alone.

When the roll motor is reversed to rewind the music sheet, speed isdesired, and hence it is common practice to provide a by-pass around thethrottle and pressure-stabilizing valves of the box. My resent inventionprovides a very simple an practical device for this purpose, consistingo a plate 1 pivoted to the bottom 10 of the box at 42 and overlying andnormally covering a ir of transversely aligned ports 43 and 44 endingfrom the ductsk 21 and 16 into the interior of the box. In the underside of the plate 41 is formed a channel 45 which is continuously incommunication with the port 43 and normally out of communication withthe port 44, but may be brought into communication with the latter so asto connect the two ports through the channel 45 by means of a pull rod4'6 connected to one end of the reroll valve 41 and extending throughone'of lthe end walls 12 of the box and connected to either a manual orautomatic actuating device.

Mounted in the bottom Wall lOvof the box isa threaded rod 47 having onits 'upper end a felt-capped head 48 and on its lower end a knurled knob49; this device conitliting an adjustable stop to limit the expandingmovement of the stabilizing pneumatic and prevent full closing of theport 17.

From the foregoing it will be seen that by my invention I have providedin small and lcompact compass a tempo-regulating mechanism manually orautomatically actuated by the plunger valve 24; au automatic pressurestabilizing device capable of fine regulation through manipulation ofthe needle vulve 40: and a simple and easily manipulated reioll valve.The box may, of course, be mounted at any suitable or convenient placewithin the pianoand readily connected up by lines of tubing to the musicroll motor, the vacuum chest or suction pump, the tempo-regulatinglever, and the ieroll lever.

While I have herein shown and described one practical and simpleembodiment of the invention, it is manifest that the structural detailsmay be varied without departure from the operative principles involvedor sacrifice of any of the inherent benefits and advantages. Hence, Ireserve all such variations, modilications and mechanical equivalents asfall within the spirit and purview of the appended claims.

I claim- 1. In a tempo regulator of the t described, the combination ofa box yfdenned with top, side and end walls, and a relatively thickbottom wall formed with a pair of air ducts in and lengthwise of itsbottom wall communicating with ports opening into ISI the interior ofsaid box and with air conduits to a roll motor and a source of suctionrespectively, and a plungerl valve slidable in one of said ducts acrossthe port through which said valve-containing duct communicates with theinterior of said box.

Q. In a tempo regulator of the type described, the combination ot a boxformed with top, side and end Walls and a relatively thick bot-tom Wall,said bottom Wall being formed with an air duct communicating at one endthrough a port with the interior ot said box and at its other end withan air conduit to a source of suction, and with a second air ductcommunicating atoneend through a slot With the interiorot said boxand atits other end With an air conduit to I a roll motor, a metal tubetorminga lining for said second air duct and having an elongated openingregistering with said slot, and

a plunger valve slidable in said tube across,

the said opening.

3. In a tempo regulator ol the type described, the combination of a` boxcontaining a vacuum chamber and -termed with air ducts in its bottomWall communica ing with the ports opening into said vacuum chamber andwith air conduits to a roll motor and a source of suction, a valveslidable in one of said ducts across the port ot said valvecontainingduct, a pressure stabilizing pneumatic suspended from the top wall ofsaid box, and a valve on the movable side ot said pneumatic controllingthe port of the other of said ducts.

4:..In a tempo regulator ofthe type described, the combination of a boxcontaining a. vacuum chamber and formed with ports communicating Withair conduits to a roll motor and a source of suctlon, a temporegulatingvalve slidable across one of said ports, a pressure stabilizingpneumatic suspended from thevtop Wall of said box, a throttle valve onthe movable side of said pneumatic .controlling the other of said ports,a spring tending to collapse said pneumatic against the pull of thesuction in said vacuum chamber and thereby open said throttle valve, andan atmospheric vent to thefinterior of said pneumatic.

5. A speciiic embodiment of claim 4, Wh erein said atmospheric vent tothe interior of said pneumatic is equipped with a regulating valveadapted to more or less throttle the fioiv ot' air through said vent.

6. In a tempo regulator of the type described, the combination of a boxcontaining a vacuum chamber and formed in its bottom Wall with portscommunicating With air conduits to a roll motor and a source. ofsuction, a tempo-regulating valve slidable across one of said ports, apressure stabilizing pneumatic suspended from the top Wall oit said box,a throttle valve on the movable side of said pneumatic controlling theother ot' said ports, a spring housing mounted on the top Wall of saidbox, a pull spring connected at its loiver end to said movable side ofthe pneumatic and at its upper end anchored in said casing, and anatmospheric vent through said top Wall to the interior ot saidpneumatic.

7. A specific embodiment of claim 6, wherein said pull spring isanchored in said spring casing through the agency of an adjusting screwmounted in the top Wall of the casing whereby the tension of the springmay be increased or reduced.

EDMOND A. HUSEBY.

